Helmets Don't Prevent Concussions - But This Tech Might..
I can't even remember the last time I had a concussion. Hopefully it wasn't recently... Seriously though I've bonked my noggin more times than I care to admit and I have actually stopped counting.
I got bucked and over shot the last jump in the Whistler biker cross course in 2001 and landed on... I assume it was my head. The last thing I remember was thinking "oh shit..." I apparently spent the next five hours asking two questions of my friend repeatedly; "what happened?" and "What's wrong with my lip?" I could push my tongue through the gaping hole in my face so my curiosity was understandable. All I recall is 'coming to' while walking with my buddies back to my hotel room in the Whistler Village about five hours after my perfectly executed lawn dart.
I was cloudy and plagued with confusion (worse than usual) and headaches for almost six months afterwards, but a much less severe bang kept me off the bike for over a year more recently. It's a frustrating injury and realizing there may be long term consequences makes brain injury somewhat disconcerting.
But we keep strapping on our helmets. Righteous motorists scold riders without brain buckets, despite going lidless themselves, but it turns out that most protective headwear designed for sport does little to protect your brain from concussion. Intuitively we think we are safer, and hardshell headgear does an effective job at preventing skull fractures and contusions when impacts are relatively low energy, but that's not what causes concussion.
Helmet manufacturers probably don't want you to know that you can sustain a concussion without any head impact at all. And in these cases it's possible that increased mass on your gigantic head could increase the odds of a brain injury. It's thought that concussion is caused when our brain, which is normally protected by cerebrospinal fluid, makes contact with the inside of your head bone. That cushion of fluid isn't enough to prevent your grey matter from sloshing around once an impact surpasses a certain threshold. And by threshold I mean a personal threshold that may even be variable. Studies have suggested that sometimes a less severe impact, even in the same location, can produce a more severe injury than a harder hit.
The bowl of boiled worms that controls everything we do, consciously and otherwise, is one of the most fragile tissue masses we possess. Your neighbourhood neurosurgeon will tell you that your cerebrum is the consistency Jello-O and on impact it bends and stretches and gets twisted out of shape.
Most of us likely wear helmets to prevent concussions and manufacturers are keen to have us believe they are effective, without ever stating that in their marketing literature. Recent developments, like MIPS and similar technologies aimed at reducing rotational force are focussed squarely on preventing concussions, but hard evidence that proves the effectiveness of these systems does not exist. Research does suggest that rotational forces may play a significant role in brain injury, so these add ons don't seem like a bad idea at all, but we are a long way from knowing how effective they are.
Just as an aside, while some of you are preparing your scathing, bitter retorts, I want to make it clear that I am not suggesting you shouldn't wear a helmet. I wear one myself. When walking to the bathroom. Helmets aren't perfect but they are all we have for the moment. So feel free to fry me for any number of other crimes, but not the one I am not committing.
There may be some hope, however. Not necessarily for mountain bikers at this point, but for those who sustain hundreds of lower energy impacts like hockey or football players. Research has revealed that male bighorn sheep and woodpeckers avoid sustaining traumatic brain injury by increasing inter-cranial pressure before crushing their skulls into hard objects. They sustain brutal impacts, apparently without so much as a mild brain cramp. This gave researchers an idea.
Two products have recently come to market that aim to increase pressure in the cranial vault - our brain's garage - by increasing blood volume in the veins that surround your brain. It's thought that a slight increase in pressure may prevent your brain from contacting the skull in low energy impacts. And the originators present compelling evidence after having high school hockey players wear the device for a season.
The first study involving athletes used a high school hockey team and advanced imaging techniques to compare pre- and mid-season changes to white matter structure in the brain. In half a season of play, each athlete received an average of 190 impacts over 20g, with an average impact level of 38g. As shown with diffusion tensor imaging (DTI), athletes not wearing the collar showed statistically significant changes in white matter microstructure of the brain, while athletes wearing the collar showed no significant changes despite similar levels in accumulated accelerations from head impacts.
You can read the entire study here. Were they paid by anyone involved with NeuroShield? Possibly, but we have no evidence of that. Is the study accurate? I skipped statistics and scientific method in University so I'm the wrong guy to ask, but the results they are pushing are impressive.
Sadly this isn't likely to be much good to mountain bikers. The impacts we sustain are far less frequent (unless you are a dirt jumper or bmxer) but often much more severe and it's unclear whether either of these devices will mitigate injury when the Gs get nastier. At the same time, any progress in this area is cause for optimism. It's heartening to know that some of us may be able to string several two syllable words into sentences when we reach age 65.